Google quietly made a huge change to its core search technology in the past month, one that affects about 90 percent of searches worldwide. Calling it Hummingbird, the technological update of Google search is designed to handle more complex queries.

Calling it the culmination of 15 years of work, the news was revealed by Amit Singhal, Google’s senior VP, one day before Google officially celebrates its 15th birthday. He spoke at a special press event today in the garage that Susan Wojcicki rented to Larry Page and Sergey Brin when they started Google in Menlo Park, California,

“Our algorithm had to go through some fundamental rethinking of how we are going to keep our results relevant,” Singhal said.

Beyond announcing that Google search is now be better at understanding concepts, relationships between concepts, and more complex questions, and despite numerous questions from reporters, Google wouldn’t give any more details about how Google Hummingbird actually works, according to various reports.

The main focus, and something that went repeated many a time, was that the new algorithm allows Google to more quickly parse full questions (as opposed to parsing searches word-by-word), and to identify and rank answers to those questions from the content they’ve indexed.